Portable mast



Feb. 1o, 1970 BLAGG 3,494,593

PORTABLE MAST Filed Jan. 29, 1968 l 3 Sheets-Sheet 1` Mgg-agg 54 ggy x'5 x5 I6 I6 FIG'. l/Sf" 7 F/G. 2 I7 8 I8 52 '8 .I lo 68 21L/lo I9 26 zo-26 68 l l 52 42 24 42 so 70 76 58 76 38 25 l s* Y 5I 58 48 46 86 72 I264 86 84 '2 w 84 l 18 L '18 L 'Ill )K )K l l, 'Il f 6j l 72 8014 82 64807g 82, Ik l 66 l` Xt 3u T X 66 n INVENTOR.

LEON BLAGG BY WM, FM) www his AroR/VEYS Feb. 10, 1970 l.. BLAGG3,494,593

PORTABLE. MAST Filed Jan. 29, 1968 3 sheets-sheet 2 'Ir T4 |46 444'INVENTOR.

LEON BLAGG ms ATTORNEYS Feb. 10, 1970 l L. BLAGG 3,494,593

PORTABLE MAST Filed Jan. 29, 1968 n s sheets-sheet s -loe -|o2 'IIF|G.3B

F|G.3A

INVENTOR.

LEON BLAGG Y BY M A16, ml/Mw hls ATTORNEYS United States Patent O3,494,593 PORTABLE MAST Leon Blagg, Channelview, Tex., assignor toSchlumberger Technology Corporation, Houston, Tex., a corporation ofTexas Filed Jan. 29, 1968, Ser. No. 701,400 Int. Cl. B66c 23/60 U.S. Cl.254--139 3 Claims ABSTRACT OF THE DISCLOSURE A portable mast for use inraising and lowering instruments in a well bore is assembled from aplurality of sections by positioning a first section in an uprightposition; elevating the first section a distance approximately equal tothe length thereof; positioning a second section underneath the firstsection in an upright position; connecting the adjacent ends of thefirst and second sections to each other; elevating the connectedsections a distance approximately equal to the length of one of thesections; positioning a third section underneath the previouslyconnected sections; connecting the adjacent ends of the second and thirdsections to each other; and repeating the foregoing elevating,positioning, and conencting steps for additional sections until the topend of the first section reaches the desired height. The mast is tiltedby guy lines so that its upper end is over the well bore, and a cable isrun from a lower sheave by the base of the mast on the opposite sidethereof from the well bore to upper sheave means at the top of the mastand into the bore. The mast substantially bisects the angle formed bythe cable in its run from the lower sheave to the upper sheave means tothe well bore. The lower sheave is mounted for swivel movement fordirecting the cable to the mast structure from any one of a plurality ofwidely separated angular positions about the lower sheave.

BACKGROUND OF THE INVENTION This invention relates to mast apparatusand, more particularly, to novel and highly-effective portable mastapparatus for use in well logging operations and the like.

In well logging operations and the like, it is necessary to raise andlower a variety of instruments and other objects. Conventional mastapparatus for accomplishing this purpose has a number of seriousdeficiencies. For example, erection of the apparatus at the site of aWell bore is time-consuming and expensive. Further, the apparatus tendswhen positioned above a well bore to place undue strain on the guy linesholding it in position. Moreover, the angular position with respect tothe mast apparatus of a winch or other means for paying out the cableused for suspending the instruments or other objects is severelylimited.

SUMMARY OF THE INVENTION An object of the invention is to remedy theshortcomings of conventional apparatus and methods noted above. Inparticular, an object of the invention is to provide a method of rapidlyand economically erecting a composite mast structure. Another object ofthe invention is to provide a portable mast apparatus for use in welllogging and the like wherein a load on the cable used for suspend-3,494,593 Patented Feb. 10, 1970 ing instruments or other objects in awell bore tends to compress the mast apparatus but not to cause unduetension in guy lines used for positioning the apparatus. A furtherobject of the invention is to provide a portable mast apparatus for usein raising and lowering instruments in a well bore facilitating theselection of any one of a plurality of widely separated angularpositions for a winch or other device for paying out a cable from whichinstruments or other objects are suspended.

The foregoing and other objects of the invention are attained bypositioning a first section of a composite mast structure having aplurality of sections in an upright position; elevating the firstsection a distance approximately equal to the length thereof;positioning a second section underneath the first section in an uprightposition; connecting the adjacent ends of the first and second sectionsto each other; elevating the connected sections a distance approximatelyequal to the length of one of the sections; positioning a third sectionunderneath the previously connected sections; connecting the adjacentends of the second and third sections to each other; and repeating theforegoing elevating, positioning, and connecting steps for additionalsections until the rst section reaches the desired height.

The objects of' the invention are further attained by the provision of abase structure positioned at least partly to one side of the well bore;mast means having a lower end pivotally mounted on the base structureand an upper end located over the well bore; means for guying the upperend in position over the well bore; upper sheave means around`whichcable can extend along a vertical line into the well bore; and lowersheave means around which the cable can pass and extend to a winch, thelower sheave means being located with respect to the lower end of themast means so that the mast means substantially bisects the angle formedby the vertical line and a line between the upper and lower sheavemeans.

The objects ofthe invention are also attained by the provision of mastapparatus for use in raising and lowering instruments in a well borecomprising a base; a mast structure supportable by the base and having aplurality of removable sections disposed in end-to-end relationship; anerecting fixture mounted on the base for supporting the mast structure;elevating means coacting between the mast structure and erecting fixturefor elevating the mast structure over vertical distances .equal tolengths of the sections; upper sheave means on the mast structure forsupporting a cable; and lower sheave means mounted on the base fordirecting the Cable to the mast structure from any one of a plurality ofwidely separated angular positions about the lower sheave means.

BRIEF DESCRIPTION OF THE DRAWING An understanding of additional aspectsof the invention may be gained from a consideration of the followingdetailed description of representative embodiments thereof, taken inconjunction with the accompanying figures of the drawing, in which:

FIG. l is a diagrammatic view in elevation of a portable mast apparatusconstructed in accordance with the invention, the apparatus being shownat an intermediate stage of its erection at the site of a well bore andalso being shown in phantom outline at a later stage of the erection;

FIG. 2 is a View similar to FIG. 1 showing the completed mastapparatusin a tilted position facilitating raising and lowering of instruments inthe well bore;

FIGS. 3A and 3B are a fragmentary view in elevation of the apparatus ofthe invention on a scale larger than that of FIGS. 1 and 2;

FIG. 4 is a sectional plan View taken along the line 4--4 of FIG. 3A ofthe apparatus of the invention, on a scale larger than that of FIGS. 3Aand 3B; and

FIG. 5 is a schematic view showing the manner in which the sheets ofdrawings containing FIGS. 3A and 3B must be juxtaposed in order toposition FIGS. 3A and 3B properly with respect to each other.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show apparatus 10constructed in accordance with the invention at successive stages of itserection at the site of a well bore. The apparatus includes a base 12and-a mast structure 14 supportable by the base and having a pluralityof removable sections 15-34 disposed in end-to-end relationship.

An erecting fixture 36 is mounted on the base 12 for supporting the maststructure. Elevating means 38 comprising winch 40 and pulley 42, a cable44, a hook 46 or the like adapted to engage the lower end of the maststructure 14, and a crank 48 or electric motor (not shown) coactsbetween the mast structure 14 and the erecting fixture 36 for elevatingthe mast structure 14 over vertical distances equal to lengths of thevarious sections 15-34.

Upper sheave means 50 is provided on the mast structure 14 at the upperend thereof for supporting working a cable 52. The upper sheave means 50comprises a pair of pulleys 54 and 56 about which the cable 52 istrained successively. Lower sheave means 58 is also provided andcomprises a pulley 60 about which the cable 52 is trained. The lowersheave means 58 is mounted on thebase 12 for directing the cable 52 tothe mast structure 14 from any one of a plurality of widely separatedangular positions about the lower sheave means 58. To this end, thelower sheave means 58 is lmounted for a swivel movement on the base 12.

The erecting fixture 36 is mounted for pivotal movement about a pin 64so that, when the mast structure 14 has reached the desired height, themast structure 14 and erecting fixture 36 can be pivoted from theposition illustrated in FIG. 1 to that illustrated in FIG. 2. In theposition of FIG. 1, the mast structure 14 and erecting fixture 36 arevertical to facilitate the addition of mast sections; in the position ofFIG. 2, they are inclined so that the cable 52 descends in a verticalline from the upper sheave means 52 into the well bore 66.

To facilitate the tilting operation, guy lines 68 and 70 on the side ofthe mast structure 14 opposite the well bore 66 are gradually paid outfrom Winches 72 and 74 respectively, while guy lines 76 and 70' aregradually reeled in by Winches 78 located to either side of the wellbore. Hand cranks 80, 82, and 84 are shown for operating the Winches 72,74, and 78 but any other suitable motive means may of course beemployed.

In the tilted position of the mast 14 shown in FIG. 2, the mast 14substantially bisects the angle formed by the vertical line traversed bythe cable 52 between the upper sheave means 52 and the well bore 66 andthe line :raversed by the cable 52 between the upper sheave means 52 andlower sheave means 58. Accordingly, a load on :he cable 52 due to thesuspension of tools and the like zherefrom, the end of the cable l52shown at the left of FIGS. 1 and 2 being held fast, tends to compressthe mast itructure 14 but not to cause rotation thereof about the Jivotpin 64.

The pivoting movement described above is further acilitated by theremoval of a support member 86 shown n a vertical position in FIG. 1 andin an inclined posiion in FIG. 2. The member 86 can be pivota-ble abouta pin 88 and, in the vertical position, prevents pivoting of the maststructure 14y and erecting fixture 36. Of course other similararrangements could 'be used. In the position of FIG. 2, however, themember 86 is clear of the erecting fixture 36 so that the erectingfixture 36 and mast structure 14 can be pivoted in response to theguidance of the guy lines 68, 70, 70', and 76.

FIGS. 3A, 3B, and 4 show the mast structure 14 and erecting fixture 36in greater detail. Both the -mast structure 14 and the erecting fixture36 are generally triangular in cross section, as FIG. 4 clearly shows.The erecting fixture 36 includes a vertical stanchion 100 at each comer.Each vertical stanchion is formed with a vertical guide 102 forming aVertical channel 104 within which lugs 106 and 108 are adapted to slidevertically.

The lugs 106 are integral with cylindrical portions 110 which are inturn integral with vertical support members 112 at the lower endsthereof. The lugs 108 are integral with cylindrical portions 114 whichare in turn integral with the upper ends of vertical support members112.

The first section 15 shown in FIG. 3B is joined to the second section 16by suitable fastening means such as swing bolts 116 or the like hingedfrom the cylindrical portions 114 and coupled to the cylindrical ends118 (see FIG. 3A) of the vertical support members 112. The cylindricalends 118 are housed within the cylindrical portions 114, the latterbeing hollow.

In a similar manner, the second section 16 is joined to the thirdsection 17, and additional sections are joined to the mast structure innumber sufficient to erect a mast of the desired height.

Additional sections are inserted at the bottom of the mast structure 14and erecting structure 36 through an open bay 120 formed at the bottomof the erecting fixture 36. In order to add an additional section of thesections assembled previously, the sections assembled previously areelevated by the elevating means 38. To this end, the hook 46 at the endof the cable 44 is made to engage a cross member 122 of the bottomsection, say the section 33, of the sections previously assembled. Thecross members 122 can be hinged at their central portions by suitablemeans (not shown) so that the sections 33 can be collapsed when not inuse into very compact units. Of course, when the members 122 arestraightened, the hinged joints can be latched so that the members 122are rigid.

By means of the crank 48 or any other suitable motive means, the cable44 is reeled in by the winch 40 over the pulley 42 so that thepreviouslyassembled sections are raised a distance approximately equalto the height of one of the sections.

An aperture 126 (FIGS. 3A and 4) is formed in the guide 102, and atemporary retaining pin 128 is inserted through the aperture 126. Byvirtue of the elevation of the previously assembled sections, the lugs108 (FIG. 3B) are elevated above the elevation of the aperture 126, andinsertion of the pin 128 is therefore adapted to retain the previouslyassembled section in the position to which they are elevated by theelevating means 38.

An additional section, say the final section 34, is then positionedbelow the previously-assembled sections (a slight additional elevationmay be given the previouslyassembled sections to permit the positioningof the section 34, shown in phantom outline in FIG. 3A, and thepreviously-assembled sections may then be lowered to feed thecylindrical portions 118 of the vertical support members 112 into thecylindrical portion 114 formed at the upper end of the vertical supportmembers 112 of the final section 34).

The lower section 34 rests on a fioor support 130. Thus, the verticalstanchions 100 do not support the weight of the completed mast structure14. The erecting fixture 36 does, however, serve to position the lowerend of the mast structure 14, the positioning function being facilitatedby the guides 102, which extend from an elevation slightly higher thanthe top of a section resting on the fioor 130 upwardly a distanceapproximately equal to the height of two of the sections of the mast 14.When the final section 34 is bolted into place in the same manner inwhich the previously-assembled sections are bolted into place, the maststructure 14 is an integral unit having the requisite strength tosuspend instruments and other objects in the well bore. The maststructure 14 and erecting fixture 36 may be triangulated bydiagonallyextending cables 132 and braces 134, respectively, in order toprovide additional strength. The brace 134 shown at the bottom of theerecting fixture 36 extends between first and second of the verticalstanchions 100 and between second and third of the vertical stanchions100 but not between the first and third of the vertical stanchions. Inthis way, the bay `120 is left open for the insertion of the sections ofthe mast structure 14.

The lower sheave means 58 is mounted for a pivoting or swivel movementas indicated at 140 and pivots as a whole about the axis of acylindrical mounting member 142. The cylindrical mounting member 142 issecured by suitable fastening means such as bolt-and-nut combinations144 passed through apertures 146 formed in the base 12. The apertures146 are at intervals of approximately 6 inches. Accordingly, theposition of the cylindrical mounting member 142 and of the lower sheavemeans 58 is adjustable in increments of approximately 6 inches, and, ifthe distance between the center line 150 of the well bore 66 and thepivot 64 (FIG. 2) is X, the distance between the pivot 64 and the lineabout which the lower sheave means 58 swivels can be adjusted to beequal to X plus or minus 3 inches. In general, the distance between thelower sheave means 58 and the pivot 64 can be made equal to the distancebetween the pivot 64 and the center line 150 of the well bore, within atolerance equal to half the spacing between the apertures 146.

Such adjustment assures that the mast means 14 substantially bisects theangle formed by the vertical line between the upper sheave means 52 andthe well bore 66 and the line between the upper sheave means 52 and thelower sheave means 60. As noted above, this arrangement assures that aload on the cable S2 tends merely to compress the mast apparatus 14 andnot to cause it to tend to pivot about the pivot 64.

A swivel movement of the lower sheave means 58 about the axis of thecylindrical mounting member 142 results in virtually no displacement ofthe portion of the cable 52 between the upper sheave means S2 and thelower sheave means 58 but permits angular movement of the portion of thecable 52 extending to the left of the sheave means 58 (FIGS. l, 2, and3A), so that there is freedom of choice of the location of a winch orother means for paying out and reeling in the cable 52.

Dismantling of the apparatus of the invention is the reverse of themethod described above. Specifically, the mast apparatus 14 is broughtto a vertical position and raised slightly by the elevating means 38,the pin 128 is inserted to hold the upper portion of the mast apparatus14, and the lower section 34 is unbolted and removed. The pin 128 isremoved, and the elevating apparatus 38 lowers the remaining sections ofthe mast apparatus 14 until the section 33 is in the open bay 120. Thepin 128 is inserted again to hold the upper portion of the mastapparatus 14 in position, and the section 33 is unbolted and removedthrough the open bay 120. Dismantling proceeds in a similar fashionuntil all of the sections 15-34 have been uncoupled from each other andremoved.

Thus, there is provided in accordance with the invention novel andhighly-effective apparatus and methods facilitating raising and loweringof instruments in a well bore. The mast sections employed in the novelmanner of the invention are conventional per se and availablecommercially. The sections are typically three feet in height and lightenough to be carried easily by two men. In accordance with theinvention, portable mast apparatus can be assembled at the site of awell bore rapidly and economically without conventional reliance uponmast trucks. It should also be noted that al1 guy lines, cat lines, andcables can be put in position on the section 15 before the sections areelevated as previously described, thereby obviating the need for anyoneclimbing the mast.

Many modifications of the representative embodiments described hereinwill occur to those skilled in the art. For example, ywhile theinvention is illustrated as applied to well logging operations conductedon dry land, it is particularly adaptable to such operations conductedfrom marine platforms. Also, while a pin 128 is shown in FIG. 3A forsupporting the upper portion of the mast apparatus 14 during periodswhen it is elevated above the floor support 130, a ratchet typeVmechanism can be substituted therefor or used in conjunction therewith.Again, the first three sections 15, 16, and 17 can be mounted in theerecting fixture 36 horizontally while the fixture 36 is in a horizontalposition. Again, guy lines 68' and 76 may be employed for guying theerecting fixture 36 and may be paid out and reeled in analogously to thepaying out and reeling in of the guy* lines 68 and 76 during the tiltingof the mast apparatus 14 and erecting fixture 36. Also, a snatch block(FIG. 3B) may be mounted near the upper end of the mast apparatus 14 forsupporting a cat line. Many other modifications of the apparatus of theinvention will readily occur to those skilled in the art. Accordingly,the invention is to be construed as including all .of the modificationsthereof within the scope of the appended claims.

I claim:

1. A portable mast apparatus for use in raising and lowering instrumentsin a well bore comprising: a base; a mast structure supportable by saidbase and having a plurality of removable sections disposed in end-to-endrelationship; an erecting fixture mounted on said base for supportingsaid mast structure; elevating means coacting between said maststructure and erecting fixture for elevating said mast structure oververtical distances equal to lengths of said sections; upper sheave meanson said mast structure for supporting a working cable; lower sheavemeans and swivel means mounting said lower sheave means on said base,said lower sheave means directing said working cable to said maststructure from any one of a plurality of widely separated angularpositions about said lower sheave means, said swivel means having aswivel axis generally aligned with the portion of said working cableextending between said lower and upper sheave means, said base includinga plurality of spaced anchoring positions whereby said lower sheavemeans may be selectively positioned thereon.

2. Apparatus according to claim 1 in which said erecting fixture ispivotally mounted on said base.

3. A portable mast apparatus for use in well logging operations or thelike wherein instruments are suspended in a well bore on a workingcable, comprising: a base structure positioned at least partly to oneside of the well bore; mast means having a lower end pivotally mountedon said base structure to one side of the well bore and an upper endlocated over the well bore; means guying said upper end in position overthe well bore; upper sheave means around which said working cableextends along a vertical line into the well bore; and a swivelmountedlower sheave means around which said working cable passes and extends toa winch, the lower sheave means being spaced apart from the lower end ofthe mast means a distance substantially equal to the spacing between thelower end of the mast means and the well bore and on the opposite sideof the mast means from the well bore so that said mast meanssubstantially bisects the angle formed by said vertical line and a linebetween said upper and lower sheave means, whereby a load on the cabletends to compress said mast means but not to cause rotation thereofabout said pivotally mounted lower end.

(References on following page) References Cited UNITED STATES PATENTSAlbert 52-118 Sago 52108 Agust 52-123 Kimblern 52-108 Woolslayer et al52--117 Great Britain.

8 Great Britain. France. France. France.

U.S. Cl. X.R.

